RECENT WORK IN AGRICULTURAL SCIENCE. 



CHEMISTRY. 



Methods of analysis of fertilizers adopted by the Association of German 

 Agricultural Experiment Stations (Landw. Vers. Stat, 60 ( /:>"',), No. 5 '/, pp. 

 871-382). — A compilation, with references to literature, of the action of the association 

 up to and including the Bfeslau meeting in September, 1904, regarding methods of 

 preparing samples, determining line meal in Thomas slag, moisture in superphos- 

 phates, water-soluble and citric acid and citrate soluble phosphoric acid, total phos- 

 phoric acid (with limits of error allowed), nitrogen in different forms, potash, lime, 

 and magnesia, iron ox id and alumina, perchlorate in nitrate of soda, and examination 

 of sulphur. 



Methods of analysis of fertilizers adopted by the Fifth International Con- 

 gress of Applied Chemistry at Berlin, 1903 {Landw. Vers. Slut., i;u [1904), 

 No. 5-6, pp. 399-404). — A brief summary is given of the general rules adopted 

 regarding sampling, determination of water, insoluble matter, phosphoric acid, iron 

 oxid and alumina, nitrogen in different forms, potash, lime, and magnesia. 



A quick method of determining potash, F. Klinkerfues ( Chun. Ztg., ?9 ( 1905 I, 

 .Vc. 7, pp. 77, 78). — A method involving the direct evaporation of the water solution 

 with platinum chlorid, washing with alcohol, dissolving the double salt in hot water, 

 decomposing with formic acid, and weighing the metallic platinum is described. 



On the determination of potash in soils, A. Levi- {Staz. Sper. Agr. Ital., 87 

 (1904), No. 7 8, pp. 595-599). — The method proposed, which is claimed to be shorter 

 than that ordinarily used, is as follows: 



Boil 50 gm. of the soil for 1 hour in 250 cc. of hydrochloric acid (1.1 sp.gr.), cool, 

 and make the volume to 500 cc; evaporate 200 cc. of the filtered solution repeatedly 

 to dryness to remove silica, take up in dilute hydrochloric acid, add barium chlorid 

 to remove sulphates, make slightly alkaline with ammonia, and add ammonium 

 carbonate to complete precipitation; make the volume to 500 cc, evaporate 250 cc. 

 of the filtered solution to dryness, and ignite to remove ammonium salts; take up in 

 dilute hydrochloric acid and again evaporate to remove excess of acid; take up in 

 water and add platinum chlorid and proceed as usual. 



Phosphoric acid determinations by the method of ignition with magne- 

 sium nitrate and by that of digestion with acids, B. L. Hartwell, A. W. 

 Bosworth, and .1. \V. Kellogg (Jour. Amer. Chem. Sue., 27 (/:>0.~>), No. .:, pp. ,.'4:- 

 .'/'/\. — A modified Neubauer method was compared on turnips and the oat plant 

 with a method in which the organic matter was destroyed by ignition with mag- 

 nesium nitrate. The results by the modified Neubauer method were on the average 

 about 3 per cent higher than by the other method, due it is thought to impurities 

 in the magnesium pyrophosphate obtained by the citric acid method. 



On the determination of calcium oxid in the presence of phosphoric acid, 

 K. K. Jarvinen (Ztechr. Anaf.yt. Chem., 43 (1904), No. 9, pp. 559-562; abs. in Jour. 

 Chem. Soc. [London'}, 88 (1905), No. - r >07, If, p. 62). — It is. pointed out that there are 

 two sources of error in the determination of calcium in the presence of phosphoric 

 acid, namely, incomplete precipitation of the lime and the contamination of the pre- 

 cipitate with phosphoric acid. 



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